A porous, cost-effective ceramic adsorbent, synthesized using
Kanuma clay and Akadama clay, was developed to adsorb ammonium
nitrogen from high concentration of ammonium polluted
wastewater. The adsorption capacity decreased when the adsorbent
dosages increased and the maximum removal efficiency
reached 19.44% at initial ammonium nitrogen concentration of
5000 mg L1 and dosage of 40 g L1. The kinetic data supported a
pseudo-second-order model (R2 = 0.9989) but showed a relatively
low fit for a pseudo-first-order model (R2 = 0.9473). The ammonium
adsorption process fitted with the Freundlich isotherm model
better than the Langmuir isotherm model. The presence of other
competitive cations (Na+, K+, Ca2+ and Mg2+) could reduce the
capacity of ammonium adsorption on the ceramic adsorbent with
a selectivity order of Na+ > K+ > Ca2+>Mg2+. On account of the
low cost, high ammonium nitrogen adsorption capacity, and good
soil amendment, it was promising to utilize the ammonium-adsorbed
ceramic adsorbent as nitrogen fertilizer directly. Therefore,
the novel ceramic adsorbent not only has good potential for
removing ammonium from industrial wastewater, but also provides
an alternative method for the nitrogen fertilizer production.